Over a period of four years, there have been 607 serious adverse events associated with the so-called “abortion pill” RU-486 reported to the FDA. These include five deaths, 68 cases of severe bleeding that required transfusions, and 66 cases of infection.

RU-486 was approved in the U.S. by the FDA in September of 2000, for the termination of early pregnancies. Since then, over 460,000 doses have been administered, while the drug has been linked to a total of eight deaths.

The 607 complaints were reported between September 2000 and September 2004. Of these there were 237 cases of hemorrhage reported, with one resulting in death. 42 were determined to be life-threatening.

Of the reported cases of infection, there were seven incidences of septic shock ( when an infection enters the blood stream and endangers major organs) two of which ended in death.

Seventeen of the reported complications occurred because women had an undiagnosed ectopic pregnancy when they took the drug. Ectopic pregnancy occurs when the fertilized egg is implanted in an area outside the uterus, and can be deadly. Eleven cases resulted in ruptures and one in death.

Diagnosis of the potentially deadly compilcations of RU-486 is often delayed by the fact that the initial warning signs of serious illness, like abdominal cramping, nausea and vomiting are also frequent side effects of the drug itself.

The report of the hazardous complications incited a protest by the ant-abortion faction to remove the drug from the market. Researcher Dr. Margaret M. Gary, remarked to WebMD that in her opinion the instances reported to the FDA make up only a fraction of the true medical problems that actually occur among RU-486 users. (The FDA has estimated that under-reporting can range as high as 90% to 99%).

Dr. Gary and co-author, Dr. Donna J. Harrison, are members of the American Association of Pro Life Obstetricians and Gynecologists, a group that advocates removal of RU-486 from the market.

In contrast, Harvard Medical School obstetrics and gynecology professor, Dr. Michael F. Greene, argued that underreporting of complications may be less of a concern with RU-486 than with many other drugs because of the controversy surrounding it.

Dr. Greene says based on the current research it is difficult to determine whether RU-486 is safe or not. He says it is not clear if the drug is more dangerous than miscarriage or surgical abortion, or whether the deaths and other reported adverse events were caused by the drug. "I don’t have a dog in this fight. But I do believe very strongly that women should have access to safe pregnancy termination rather than being forced to undergo unsafe pregnancy termination. If the safest way of terminating a pregnancy turns out to be surgical, then so be it. But until we have more compelling data, no one should leap to conclusions."

The manufactures of the drug, also called Mifeprex declined to comment. Federal officials announced that the FDA is currently investigating the deaths and the reported negative events.

In November, considerable attention was focused on Mifeprex because of multiplte deaths among users of the drug from the same deadly bacteria, Clostridium sordellii, which is a rare and lethal bacterium for which there is no known cure once an infection takes hold.

At that time, the FDA as well as the Centers for Disease Control and Prevention (CDC) announced their intention to launch investigations into the possible link.

Mifeprex (RU-486), as an abortion pill, has been shrouded in controversy since 1996 when the federal advisory committee that recommended its approval was forced to meet under the protection of federal marshals.

Until now, no one had ever suggested or suspected that the drug and the infection might be linked in some way. With the confirmation that at least five women had died from Clostridium sordellii infections within days of taking the drug, medical experts were faced with far more than a coincidence. It had turned into a public safety issue that required a satisfactorily explanation.

Since four of the five deaths occurred in a cluster between September 2003 and May 2005 in California, there was speculation that contamination may have played a role in the fatal infections. Testing by the FDA, however, proved negative for any such contamination.

As a result, the decision was been made to convene a special meeting early in 2006 at which officials from the FDA and CDC will examine what has become a perplexing medical mystery. No doubt, the fifth death, which occurred in Canada during clinical testing of the drug in 2001, will now be reexamined.

In each of the deaths, Clostridium sordellii infected the woman’s uterus, flourished, and then entered their bloodstreams. Death occurred in each case within one week of taking the drug.

This deadly bacterium can cause nausea, vomiting, diarrhea, and weakness. Since fever may not occur, however, victims often succumb to toxic shock without ever realizing how sick they really were. Once the infection has flourished, antibiotics are often ineffective because even in death, the bacteria continue to release deadly toxins.

Many experts are concerned about these revelations for a number of reasons. One is that other similar deaths may be going unreported because the association between the drug and the infection has not been made. A second is the under-reporting issue discussed above.A third is that some researchers believe the drug itself impairs the immune system and makes patients more vulnerable to infection with Clostridium sordellii. Dr. James McGregor, of the University of Southern California, discussed that theory earlier this year in two medical publications.

As a result, critics of the drug are again calling for its removal from the market pending the outcome of the combined FDA and CDC probe.

Warnings about the drug’s possible link with Clostridium sordellii were placed on Mifeprex’s label in July, and the FDA updated this information on its Web site on November 4, without announcement, after it discovered that all four California deaths involved the Clostridium sordellii bacterium.